TWI262966B - Electrochemical electroplating method - Google Patents

Abstract

An electrochemical electroplating method is applied in forming a copper layer, including the following steps: first, providing a substrate having a groove. Then, forming a copper seed layer on the groove, and carry out the electrochemical electroplating steps, providing a periodic wave with a positive impulse and a negative impulse to the copper seed layer via an electroplated electrode. The frequency of the periodic wave is between 0.5 Hz and 40 Hz, and the amplitude of the negative impulse is between 1 to 7 voltages so as to form the aforementioned copper layer.

Description

1262966 V. INSTRUCTION DESCRIPTION u) [Technical Field to Which the Invention Is Ascribed] The present invention relates to an electrochemical plating method, and more particularly to an electrochemical plating method for performing periodic plating and electrolysis. [Prior Art] In the manufacturing process of a semiconductor element, since the line width requirement becomes narrower and narrower, copper metal has replaced aluminum metal as a preferable wire material in a wire process of 0.18 μm or less. To meet the requirements for time (RC) delay. Especially when the line width is small, the chemical vapor deposition technique is used to form the copper conductive layer to obtain a relatively flat film layer. Generally, the technique of chemical vapor deposition to form a copper layer is to use a chemical containing organic substances as a source gas. The formed copper layer has a high resistivity, especially when the thickness of the copper layer is reduced, the resistivity is further increased. Furthermore, the residue generated after chemical vapor deposition causes problems in adhesion between the copper layer and the subsequently deposited thin film layer, and the chemical vapor deposition cost is high. Therefore, at present, electrochemical plating (ECP) technology is often used in the industry to form a copper conductive layer, which is low in cost and does not increase the resistivity of the copper layer, but a region to be deposited must have a conductive layer or A conductive seed layer is formed. However, the electrolyte usually has some impurities, such as organic substances, such as organic substances. If the above substances are attached to the formed copper conductive layer, the resistivity of the copper conductive layer is high, especially when the thickness of the copper layer is reduced. The rate will be even stronger. Conventional technology uses an electrochemical plating that alternates between electroplating and electrolysis

0503-716nW(Nl) ; TSMC2001 -1058 ; Robert.ptd Page 4 1262966 ——-- V. Description of invention (2) : ΐ ΐ ; ΐ : 属 is a wire. Referring to Fig. 1, Fig. 1 shows the intention to use the " Here, the electroplating process is required, and the seed layer 12 is taken as an example. The electroplating wafer 16 is supplied to the electrochemical electrode 16 to be placed in the electrolyte 14, and then the electroplating is performed by electroplating with a copper seed layer 12 as shown in Fig. 2. Do not. The father performs the electroplating and electrolysis of the electrochemical shovel f, 1 is the electricity supplied by the electrode 16? Plating = APPLIED MATFpt at 〇 Only a combination of electric and erroneous, for example, when the electricity is used, the ECP device sold at this time. When the voltage supplied is positive. And when the species = the action of the electric ore, the copper layer gradually undergoes the action of electrolysis: when the position is negative, 'the copper seed layer 12 is held at this time, here::,] = the copper metal on the surface of the copper layer will be ionized For the effect of copper from the tip discharge, the above: or the tip, due to the negative electric appliance to produce the protrusion or tip. Furthermore, the negatively charged impurities in the solution, negative: J: f electricity can repel the surface of the electrolytic copper, so it is necessary to properly switch the frequency formed by the plating. The negative frequency of the conventional technique is 〇·32Ηζ. , , _ is 25V, and the voltage is dyne/cm2 when the stress of the copper layer formed by the conventional technique is _ ς = stress test. The value of this generation of sound reduction is -1.5 0 9E08 After the copper layer performs the ECP process = the impurities of the f. The reason is that when it is low, if it is copper? Add a tempering process. When the temperature drops by ΙΠ, the degree of shrinkage is greater than the base around it. 0503-7161TWF(Nl); TSMC2〇〇l-i〇58; Robert. ptd Page 5 1262966

Bottom, this is the tensile force of the metal material (the compression force of the substrate, which represents the extrusion of the substrate, the degree of visibility, showing the necessary characteristics, so the steel layer is pulled), however, if the copper layer is less than the surrounding The stress contained in the interior of the copper layer is excessively controlled by impurities, and the stress applied to the inside of the copper layer should be the substrate at which the stress is applied, and the shrinkage affects the shrinkage content when it is cooled. SUMMARY OF THE INVENTION The main object of the present invention is to disclose the electrochemical voltage and the higher frequency process, and thus, an electrochemical plating process. First, a base trench is provided to form a copper seed. A seed layer is provided by a battery electrode, and the periodic wave ′ and the negative pulse shocks the copper layer. In view of the above, in order to solve the above problems, an electrochemical plating method is provided. According to the method of the present invention, the electrochemical power generation system is used to effectively improve the purity of the formed copper by using the positive and negative switching frequency of the negative pulse of the conventional pulse. . In order to achieve the above object, the present invention is directed to forming a copper layer comprising the following steps, the above having a trench. Next, in the above layer, and then performing an electrochemical plating step, the period of the positive pulse and the negative pulse to the steel is in the range of 0·5 Ηζ 40 40 Hz, and the frame is in the range of 1 to 7 volts. [Formulation] Embodiments·· Fig. 3 shows an operation flow chart according to the present process. And the 4th figure ~ the 4th Γ FI total blessing - Shangyu Lane class 4 brother figure does not correspond to the 3rd figure

1262966

1262966 —--- V. Description of invention (5) is copper ion. According to the present invention, the absolute value is less than 7 volts, and the electrical pulse supplied by the electrical negative pulse is between 5 and 4 Hz. The preferred embodiment has a frequency range of volts and the voltage waveform frequency is 4 Hz, H. The voltage supplied is approximately 1-10 minutes for a period of one. Electrochemical plating is performed. At this time, if the surface of the copper layer has the effect of the discharge of the inner-to-one end, the above-mentioned protruding protrusions or tips are unnecessary protrusions due to c-copper. ί 行 ionization, therefore there is a book: there is another advantage, this advantage lies in the negative Ray two again, the application of negative and negative negative impurities, to avoid negative ion impurities attached = ^ enough to repel the electrolyte! Second, the electrode 2 must be properly controlled Electricity = Jin: Cheng copper table ί. In the embodiment of the present invention, the electric dust wave; the positive and negative electric switching frequency has the effect of improving the purity of the copper layer. When the copper plug is exposed to stress test, the force formed by the steel=mine method is found to be i., 08 dyne/cm2. On this day, the stress of == is less, and is relatively small. The reason is that when the copper layer performs the ECP process, a tempering process, when the temperature is lowered, it must be added after the clothing is more than 苴 _, the right is pure copper, and the stress of the shrinkage layer at this time should be The characteristics of the metal material, so the stress on the copper layer formed by copper is the case of i-shrinkage, showing that =I month has effectively reduced the impurity content inside the copper layer. Figure 7 is a diagram showing the voltage value of the negative pulse corresponding to the voltage frequency supplied by the electrode. As shown in Figure 7, the area of the diagonal line

1262966 V. Inventive Note (6) The domain represents the other part of the sub-system technology to make the domain c C), the purity of the technique described in the stress test test example of the embodiment is further limited to The present invention is not deviated from the hair accessories, and therefore the present invention prevails. The resulting copper layer performs stress testing as the area of tension, while the table performs stress testing as the area of compressive force. According to the parameters of the transfer, the purity of the copper layer formed by the stress test result is a poor result, and according to the electrochemical plating method of the present invention, the parameter used is located in the region of the tension (D). Point), showing that the copper layer formed by the electrochemical plating method according to the present invention has much better advantages than the conventional one. Although the invention is disclosed in the preferred embodiment as above, it is not intended to be used in the scope of the present invention. The slashed areas are applicable to the scope of application. Anyone who is familiar with the art, within the spirit and scope of the Ming Dynasty, can make a few changes and protect the scope of the invention.

0503-7161TWF(Nl); TSMC2001-1058; Robert.ptd Page 9 1262966 BRIEF DESCRIPTION OF THE DRAWINGS In order to make the above objects, features and advantages of the present invention more comprehensible, a preferred embodiment is described below The drawings are described in detail as follows: Illustration: Fig. 1 is a schematic view showing electrochemical plating using staggered electroplating and electrolysis. Fig. 2 is a view showing the voltage waveform of the electrode supply voltage to the copper seed layer in the conventional technique for performing electroplating of electroplating and electrolysis. Figure 3 is a flow chart showing the operation of a semiconductor electroplating process in accordance with an embodiment of the present invention. 4A to 4C are sectional views showing the semiconductor corresponding to Fig. 3. Figure 5 is a schematic view showing electrochemical plating using staggered electroplating and electrolysis according to an embodiment of the present invention. Fig. 6 is a view showing a voltage waveform of an electrode supply voltage to a copper seed layer in performing electrochemical plating for electroplating and electrolysis according to an embodiment of the present invention. Figure 7 shows a graph of the voltage value of the negative pulse corresponding to the voltage supplied by the electrode. DESCRIPTION OF SYMBOLS: 1 0 , 2 0~ wafer; 2 1~ trench; 1 2, 2 2~ copper seed layer;

0503-716nW(Nl) ; TSMC2001-1058 ; Robert.ptd Page 10 1262966 Schematic description 1 4, 2 4 ~ electrolyte; 1 6, 2 6 ~ electrode. Page 11 0503-7161TWF(Nl) ; TSMC2001-1058 ; Robert.ptd __1

Claims (1)

1262966 /,, Shenjing patent scope 1 - an electrochemical plating method suitable for forming a copper layer, comprising the steps of: providing a substrate having a trench; a square; the trench forming a copper seed layer, and - performing an electrochemical plating step, Providing a periodic wave having a positive pulse and a negative pulse to the copper seed layer by a plating electrode, wherein the frequency of the periodic wave is less than 40 Hz, and the amplitude of the negative pulse is less than 7 volts to form the copper layer . 2 · The above groove 3 as in the application · · The above groove 4 as claimed in the application · · The above copper crystal according to the application 5. As described in the above cycle 6. As described in the above negative pulse 7 · - Steps: Please patent For the patent range of the scope of the non-equipment, please ask the patent for the thickness of the layer. Please use the electrochemical plating method described in the first paragraph of the electromagnetic wave of the patent Fang Chongzhi, which is formed in the process of the engraving process. The electrochemical plating method according to Item 1, which is located between 200 Å and 1 00 Å. The electrochemical plating method described in the first item ranges from 30 angstroms to 20 angstroms. The range of the electrochemical plating method described in the first item is between 0.5 Hz and 40 Hz. The electrochemical plating method described in the first item is between 1 volt and 7 volts. a bismuth plating method suitable for forming a copper layer, including the underlying layer thereof; and a plating electrode providing a positive pulse seed layer, the frequency of the periodic wave providing a substrate having a trench; forming a copper crystal in the trench The seed layer performs an electrochemical plating step by pulsing a periodic wave of a negative pulse to the copper crystal 0503-7161TWF(Nl) ; TSMC2001-1058 ; Robert.ptd Page 12 1262966 6. The scope of application is within the range of 0.5 Η z~4 Ο Η z, and the amplitude of the above negative pulse is at 1 volt. Within the range of 7 volts to form the above copper layer. 8. The electrochemical plating method of claim 7, wherein the trenches are formed by an anisotropic etching process. 9. The electrochemical plating method of claim 7, wherein the groove depth range is between 200 Å and 1 00 Å. The electrochemical electrode bonding method as described in claim 7 wherein the copper seed layer thickness ranges from 30 angstroms to 200 angstroms. 0503-7161TWF(Nl) ; TSMC2001-1058 ; Robert.ptd Page 13